ESP32 with FTDI programmer

One also needs to connect DTR and RTS pins. Below is a circuit schematic on how to achieve proper data transmission on a ESP32 MCU boards Using a CH340C SOP-16.

from this author here: https://en.kohacraft.com/archives/make-a-circuit-using-ch340c-for-esp32-writingsuccess.html

This can be done using the CH340K MSOP-10 (10 pin; smaller package).

To add a flash LED status one needs to connect the "EMAC_RX_DV" pin. In the ESP-32 WROOM-32x board is on GPIO 27, PIN 12. See the figure below on how is made for an ESP-32S:

To upload a program to the ESP-32, manually, ie, without the DTR/RTS connections,

• open the Arduino IDE Serial Monitor
• Hold-down the “BOOT” button
• Press the “ENABLE” button once
• Release the finger from the “BOOT” button

Do you see the following message in your Arduino IDE Serial Monitor?

“rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))
waiting for download”

After seeing that message, press the “Upload” button in your Arduino IDE to upload a new sketch.

In those boards/with that setup, after uploading a new sketch, press the “Enable” button to restart the ESP32 and run the new sketch uploaded.

the original answer can be found here: https://rntlab.com/question/a-fatal-error-occurred-failed-to-connect-to-esp32-timed-out/

EDIT:

... in the meantime i got time to design in KiCad a fully working MCU firmware downloader that is suitable for ESP32. This one uses the CH340K IC for USB to UART TTL data sync. One can find drivers for that IC here: http://www.wch-ic.com/downloads/CH341SER_ZIP.html

here's my GitHub repo with the KiCad project files available to download: https://github.com/aeonSolutions/AeonLabs-MCU-Burner-USB-to-UART-TTL

I see your connections and there is a problem.

Uploading code to the ESP32 is not the same as uploading code to an Arduino or ESP8266 where we used only RX and TX pins. To upload code to the ESP32 there are some other pins that are used:

1. RXD0
2. TXD0
3. GPIO 13
4. GPIO 15
5. GPIO IO0
6. EN
7. VCC
8. GND

• FTDI PIN ---------------> ESP32 PIN

1. CTS -----------------> GPIO 15
2. RTS -----------------> GPIO 13 AND GPIO IO0
3. RX -----------------> TXD0
4. TX -----------------> RXD0
5. DTR -----------------> EN
6. VCC -----------------> Vin
7. GND -----------------> GND

After making these connections you can upload code successfully. Don't forget to press the boot button for a while, when starting to upload code.

Assuming that you are using a standalone ESP32, no boot or reset button, what I would suggest is pull down GPIO 2 and GPIO 0 to ground, and the standard connection as described above (Tx to FTDI Rx and Rx to FTDI Tx)

Power OFF and ON the supply, you should read over serial (Coolterm or Serialmonitor, etc.) at 115200 baud.,

ets Jun  8 2016 00:22:57
rst:0x1 (POWERON_RESET),boot:0x3 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_REO_V2))

ie. you are in boot mode, if you don't power off and on again until you do!

Now, connect

EN to RTS.

GPIO0 to DTR.

GPIO 2 is still ground or floating.

and Tx and Rx as said above.

Try flashing now......

I connected the GPIO0 directly to the GND and used the 5v power. It worked OK.

Yes, you can program the ESP32 DevKit v1 using an FTDI (Future Technology Devices International) USB-to-Serial converter. The ESP32 DevKit v1 typically comes with a built-in USB-to-UART bridge, so you don't necessarily need an external FTDI module. However, if you have an FTDI module and want to use it for programming, you can do so by connecting it to the appropriate pins on the ESP32 DevKit v1.

Here are the general steps to program the ESP32 DevKit v1 using an FTDI module:

Identify the Pins:

Locate the following pins on the ESP32 DevKit v1: TXD (Transmit Data) RXD (Receive Data) EN (Enable) GND (Ground) 3V3 (3.3V) Connect the FTDI Module:

Connect the TXD pin of the FTDI module to the RXD pin of the ESP32. Connect the RXD pin of the FTDI module to the TXD pin of the ESP32. Connect the EN pin of the ESP32 to the 3.3V output of the FTDI module. Connect the GND pins of both the FTDI module and the ESP32 together. Connect the 3V3 pin of the ESP32 to the 3.3V output of the FTDI module. Select the Appropriate COM Port:

Connect the FTDI module to your computer via USB. Open the Arduino IDE or your preferred programming environment. Select the COM port corresponding to the FTDI module in the IDE. Select the Board:

In the Arduino IDE, go to "Tools" > "Board" and select "ESP32 Dev Module" or the specific variant that matches your ESP32 DevKit v1. Upload Your Code:

Write or open your Arduino sketch. Click the "Upload" button to compile and upload your code to the ESP32. Monitor Serial Output:

If your code includes serial output (e.g., Serial.begin()), you can open the serial monitor to view the output. Remember that the specific pin mappings might vary based on the ESP32 variant or board version. Always refer to the documentation provided by the manufacturer for the correct pin connections. Additionally, make sure that the FTDI module you are using operates at 3.3V to avoid damaging the ESP32, as it typically works with 3.3V logic levels.